Fan speed testing system and method

Abstract

A fan speed testing system for testing a testing fan includes a testing fan, a collecting module, a processing module, a converting module; and a displaying module. A label is attached to the testing fan and capable of rotating with the testing fan. The collecting module is configured to collect light reflected off of the label as the fan rotates in order to produce a pulse signal. The processing module is configured to adjust the pulse signal to be a standard square wave. The converting module is configured to obtain a fan speed data of the testing fan according to conversion times between high levels and low levels of the standard square wave. The displaying module is configured to display the fan speed data.

1. A fan speed testing system for testing a testing fan, a label attached to the testing fan and capable of rotating with the testing fan, the fan speed testing system comprising:
 a collecting module, the collecting module is configured to collect light reflected off of the label as the testing fan rotates in order to produce a pulse signal; 
 a processing module configured to adjust the pulse signal to be a standard square wave; 
 a converting module configured to obtain a fan speed data of the testing fan according to conversion times between high levels and low levels of the standard square wave during a given period of time; 
 a displaying module configured to display the fan speed data; 
 the collecting module comprises a light-emitting diode and a phototransistor; light from the light-emitting diode is capable of reflecting off of the label, and the phototransistor is capable of being periodically turned on after collecting light reflected off of the label in order to produce the pulse signal; 
 an emitter of the phototransistor is connected to ground, and a collector of the phototransistor is connected to a first voltage source via a resistor; and 
 the processing module comprises a first comparator and a second comparator; a first negative input terminal of the first comparator is connected to the collector of the phototransistor, and a first positive input terminal of the first comparator is connected to a second voltage source; a first output terminal of the first comparator is connected to a second positive input terminal of the second comparator, a second negative input terminal of the second comparator is connected to a second output terminal of the second comparator, and the second output terminal is connected to the converting module. 
 
     
     
       2. The fan speed testing system of  claim 1 , wherein a potentiometer is connected between the first output terminal and the second positive input terminal, a first terminal of the potentiometer is connected to the first output terminal, a second terminal of the potentiometer is connected to ground, and a wiper of the potentiometer is connected to the second positive input terminal. 
     
     
       3. The fan speed testing system of  claim 1 , wherein a potentiometer is connected between the first positive input terminal and the second voltage source, a first terminal of the potentiometer is connected to the second voltage source, a second terminal of the potentiometer is connected to ground, and a wiper of the potentiometer is connected to the first positive input terminal. 
     
     
       4. The fan speed testing system of  claim 1 , wherein the converting module is configured to collect the conversion times between high levels and low levels of the standard square wave and calculate the fan speed data according to the conversion times during the given period of time. 
     
     
       5. The fan speed testing system of  claim 1 , wherein the displaying module comprises a plurality of seven-segment displays to display the fan speed data. 
     
     
       6. A fan speed testing method for testing a testing fan having a label able to reflect light, the label capable of rotating with the testing fan, the fan speed testing method comprising:
 providing a collecting module, a processing module, a converting module, and a displaying module; 
 collecting light reflected off of the label via the collecting module in order to produce a pulse signal as the testing fan rotates; 
 adjusting the pulse signal to be a standard square wave via the processing module; 
 obtaining a fan speed data of the testing fan via the converting module according to conversion times between high levels and low levels of the standard square wave during a given period of time; and 
 displaying the fan speed data via the displaying module; 
 wherein the processing module comprises a first comparator and a second comparator; a first positive input terminal of the first comparator is connected to a second voltage source; a first output terminal of the first comparator is connected to a second positive input terminal of the second comparator, a second negative input terminal of the second comparator is connected to a second output terminal of the second comparator, and the second output terminal is connected to the converting module. 
 
     
     
       7. The fan speed testing method of  claim 6 , wherein the collecting module comprises a light-emitting diode and a phototransistor; light from the light-emitting diode is capable of reflecting off of the label; the phototransistor is capable of being periodically turned on after collecting light reflected off of the label in order to produce the pulse signal. 
     
     
       8. The fan speed testing method of  claim 7 , wherein an emitter of the phototransistor is connected to ground; a collector of the phototransistor is connected to a first voltage source via a resistor; and a first negative input terminal of the first comparator is connected to the collector of the phototransistor. 
     
     
       9. The fan speed testing method of  claim 8 , wherein a potentiometer is connected between the first output terminal and the second positive input terminal, a first terminal of the potentiometer is connected to the first output terminal, a second terminal of the potentiometer is connected to ground, and a wiper of the potentiometer is connected to the second positive input terminal. 
     
     
       10. The fan speed testing method of  claim 8 , wherein a potentiometer is connected between the first positive input terminal and the second voltage source, a first terminal of the potentiometer is connected to the second voltage source, a second terminal of the potentiometer is connected to ground, and a wiper of the potentiometer is connected to the first positive input terminal. 
     
     
       11. A fan speed testing system for testing a testing fan, a label attached to the testing fan and capable of rotating with the testing fan, the fan speed testing system comprising:
 a collecting module, the collecting module is configured to collect light reflected off of the label as the testing fan rotates in order to produce a pulse signal; 
 a processing module configured to adjust the pulse signal to be a standard square wave; 
 a converting module configured to obtain a fan speed data of the testing fan according to conversion times between high levels and low levels of the standard square wave during a given period of time; and 
 a displaying module configured to display the fan speed data; 
 wherein the processing module comprises a first comparator and a second comparator; a first positive input terminal of the first comparator is connected to a second voltage source; a first output terminal of the first comparator is connected to a second positive input terminal of the second comparator, a second negative input terminal of the second comparator is connected to a second output terminal of the second comparator, and the second output terminal is connected to the converting module. 
 
     
     
       12. The fan speed testing method of  claim 11 , wherein the collecting module comprises a light-emitting diode and a phototransistor; light from the light-emitting diode is capable of reflecting off of the label; the phototransistor is capable of being periodically turned on after collecting light reflected off of the label in order to produce the pulse signal; an emitter of the phototransistor is connected to ground; a collector of the phototransistor is connected to a first voltage source via a resistor; and a first negative input terminal of the first comparator is connected to the collector of the phototransistor.